The ACT Conservation Council and campaigner 350.org said the recommendation from the Legislative Assembly's budget estimates committee would keep pressure on the Barr government to end investments in 65 of the top 200 worst-performing companies, including Exxon Mobil, Whitehaven Coal, Peabody, Glencore, Anglo American and Santos.

Ahead of Chief Minister Andrew Barr presenting the government's response to the estimates committee report in the assembly on Tuesday, Conservation Council assistant director Larry O'Loughlin said despite the territory leading Australia on climate action, it remained invested in some of the world's dirtiest companies.

"The government needs to develop and make public a plan to get out of these investments, which contradict the ACT's good climate-change policies," he said.

"A sensible timeline would be for the ACT government to announce a plan by the end of 2015 that delivers full divestment from fossil fuels by 2018."

Spokesman for 350.org Canberra Josh Creaser said moves such as reducing greenhouse gas emissions 40 per cent from 1990 levels within five years and drawing 90 per cent of energy from renewable sources were welcome goals, but more could be done sooner.

"We think it is one of the strongest signs yet for the government to take this issue seriously and get the ACT's money out of investments in fossil-fuel companies," he said.

Mr Creaser welcomed other developments, including moves by the Commonwealth Bank to stop advising to Australia's biggest coal project, Adani Mining's proposed Carmichael Mine in Queensland.

"We call on the other big banks, ANZ, National Australia Bank and Westpac, to also rule out ever having involvement in this project and we think for all the big four banks it's time for them to think how they will move beyond fossil-fuel investments.

"There is a lot more work to be done," Mr Creaser said. The group has held demonstrations at the assembly during the past two years, joined by community organisations such as unions, conservation groups and churches.

Mr Barr said the government would make "well-researched, sustainable investments" that deliver a good return. He said direct investment in fossil fuels and the source of carbon emissions would be reduced eventually, adding to cuts already completed.

"We acknowledge the impacts of fossil fuels on the climate," Mr Barr said. "That's why we are committed to increasing renewable energy sources in the territory to 90 per cent.

"The ACT government has made significant progress in implementing and applying our responsible investment policy framework to the management and ownership of our share investments.

The government will periodically consider its investment policy as part of a program.

"Our plan in relation to the timing of adjustments to our framework and changes in actual investment exposures will not be shared publicly due to commercial sensitivities," Mr Barr said.